Revise, Reflect, Refine
Q1. Would it be a good idea to use paper-like materials for making cooking utensils?
Answer:
No, it would not be a good idea to use paper-like materials for making cooking utensils. Paper is soft, can be easily compressed, and is not heat-resistant. It would catch fire or get damaged when placed on a stove or used for cooking. Cooking utensils need to be made from hard, heat-resistant materials like metal or clay.
Q2. Why cannot a tumbler made of cloth be used for storing water?
Answer:
A tumbler made of cloth cannot be used for storing water because cloth is a porous and absorbent material. Water would seep through the fabric or be absorbed by it, causing the tumbler to become wet and leak. The cloth would not be able to hold the water in a contained manner.
Q3. Can a cricket ball be used to play tennis?
Answer:
No, a cricket ball cannot be used to play tennis. A cricket ball is harder, heavier, and does not bounce as high as a tennis ball. Tennis requires a ball that is lighter, softer, and can bounce well on a tennis court. Using a cricket ball in tennis would not work properly and could be dangerous.
Q4. Are all lustrous materials metals?
Answer:
No, not all lustrous materials are metals. Some non-metals can also be made shiny by polishing or coating them with thin layers of plastic, wax, or other materials. For example, a polished plastic surface may shine, but it is not a metal. However, materials with natural lustre are usually metals.
Q5. Why did Ghulan, Sheeta and Sara choose these places to hide?
Answer:
Ghulan hid behind a wall, Sheeta hid behind a big tree, and Sara hid behind a frosted glass door. They chose these places because the wall and the tree are opaque materials that do not allow light to pass through, making them completely invisible to others. The frosted glass door is translucent, which means they can be seen only as hazy shapes and not clearly, providing a good hiding spot.
Q6. Do you think it would be possible for Sheeta’s brother to see her and her friends through a closed wooden window of the house?
Answer:
No, it would not be possible for Sheeta’s brother to see her and her friends through a closed wooden window. Wood is an opaque material that does not allow any light to pass through. Therefore, you cannot see through a wooden window at all.
Q7. Is water transparent? Can it be made opaque?
Answer:
Yes, water is transparent as we can see clearly through it. Water can be made opaque by adding materials that do not dissolve in it, such as mud, chalk powder, or sand. When such materials are mixed in water, the mixture becomes cloudy and we cannot see through it clearly, making it opaque.
Q8. Does everything you put in water disappear?
Answer:
No, not everything you put in water disappears. Some materials like sugar and salt dissolve in water and disappear because they are soluble. Other materials like sand, chalk powder, and sawdust do not dissolve in water. They remain visible and settle at the bottom or float, making them insoluble in water.
Q9. Do liquids like oil, vinegar and honey dissolve in water? Explore.
Answer:
Oil does not dissolve in water. When oil is added to water, it forms a separate layer on top because oil is lighter and does not mix. Vinegar (which is mostly water with acetic acid) mixes completely with water because it is soluble. Honey dissolves in water, but it takes some time to mix as it is thick and viscous. So, different liquids behave differently when mixed with water.
Q10. What about the gases present in water?
Answer:
Some gases are soluble in water while others are not. For example, oxygen gas dissolves in water, which is very important for the survival of animals and plants that live in water. Carbon dioxide also dissolves in water. However, not all gases dissolve easily in water.
Q11. Why is the level of water different in the two tumblers?
Answer:
The level of water is different in the two tumblers because the amount of water poured into each tumbler is different. Even though both tumblers have the same capacity (volume), one contains less water (half-filled) and the other contains more water (almost fully filled). The volume of water occupies different amounts of space.
Q12. Why was I not able to transfer water from the jug into an empty water bottle completely?
Answer:
You were not able to transfer all the water from the jug into the empty water bottle because the bottle has a limited capacity (volume). The water from the jug likely has a greater volume than the empty space available inside the bottle. Once the bottle is full, no more water can be added as there is no further space to occupy.